Medium-term follow-up of renal function in hypoxaemic congenital heart disease patients

Introduction Hypoxaemic congenital heart disease (CHD) patients are at higher risk of complications. The aim of this study was to compare and follow-up blood and 24-hour urine analytical data in hypoxaemic and non-hypoxaemic CHD patients.

The inclusion criteria for this study were as follows: patients older than 14 years of age with a structural CHD with or without associated hypoxaemia.

In total, 27 hypoxaemic and 48 non-hypoxaemic CHD patients were included in order to compare blood and 24-hour urine analytical data. Among hypoxaemic patients, 13 (48.1%) were male, two (7.4%) had diabetes mellitus, one of whom was a smoker, one (3.7%) had systemic arterial hypertension, and 11 (40.7%) showed pulmonary arterial hypertension. The mean follow-up time was 3.1±1.9 years. Hypoxaemic CHD patients showed higher proteinuria concentrations (g/24 hours) (0.09 (0.07; 0.46) versus 0.08 (0.07; 0.1), p=0.054) and 24-hour albumin excretion rate (µg/min) (16.5 (11.2; 143.5) versus 4.4 (0.0; 7.6), p<0.001) compared with non-hypoxaemic CHD patients; however, no significant differences were found in the proteinuria levels and in the 24-hour albumin excretion rate in CHD patients with associated hypoxaemia, both at baseline and at follow-up. When divided into groups, hypoxaemic patients with palliative shunts showed significantly higher proteinuria concentrations compared with hypoxaemic patients not operated on or with Fontan procedures (p=0.01). No significant differences were seen in 24-hour proteinuria and 24-hour albumin excretion rate during the follow-up of patients with palliative shunts.

Hypoxaemic CHD patients have significant higher 24-hour proteinuria concentration and 24-hour albumin excretion rate compared with non-hypoxaemic CHD patients. Among hypoxaemic CHD patients, those with palliative shunts showed the highest 24-hour proteinuria concentrations.